CHADS2 and CHA2DS2-VASc risk factors to predict first cardiovascular hospitalization among atrial fibrillation/atrial flutter patients

Limited data exist concerning risk factors for cardiovascular (CV) hospitalization in patients with atrial fibrillation (AF) or atrial flutter (AFL). The aim of this retrospective cohort evaluation was to assess whether patient characteristics and risk factors, including CHADS(2) (congestive heart failure, hypertension, age ≥75 years, type 2 diabetes, and previous stroke or transient ischemic attack [doubled]) and CHA(2)DS(2)-VASc (congestive heart failure; hypertension; age ≥75 years [doubled]; type 2 diabetes; previous stroke, transient ischemic attack, or thromboembolism [doubled]; vascular disease; age 65 to 75 years; and sex category) scores, identified patients with AF or AFL at risk for CV hospitalization. Claims data (January 2003 to June 2009) were evaluated to identify patients aged ≥40 years with ≥1 inpatient or ≥2 (within 30 days of each other) outpatient diagnoses of AF or AFL and an absence of diagnosis codes related to cardiac surgery within 30 days of AF or AFL diagnosis. Risk factors for first CV hospitalization in the 2-year period after diagnosis were assessed using univariate and multivariate analyses. Overall, 377,808 patients (mean age 73.9 ± 12.1 years) were identified, of whom 128,048 had CV hospitalizations. CHADS(2) and CHA(2)DS(2)-VASc scores were the top 2 predictors of first CV hospitalization after AF or AFL diagnosis. Hospitalization risk was increased 2.3- to 2.7-fold in patients with CHADS(2) scores of 6 and approximately 3.0-fold in patients with CHA(2)DS(2)-VASc scores of 9 compared to patients with a score of 0. These increases were maintained essentially unchanged throughout the 2-year follow-up period. In conclusion, CHADS(2) and CHA(2)DS(2)-VASc scores were predictive of first CV hospitalization in patients with AF or AFL and may be helpful in identifying "at-risk" patients and guiding therapy.     

成人先心病合并典型心房扑动患者导管消融术后新发心房颤动的临床研究

目的 探讨成人先天性心脏病(先心病)合并典型心房扑动(房扑)患者导管消融术后新发心房颤动(房颤)的发生率和高危因素.方法 选取2013年7月至2019年7月于河南省人民医院心血管内科接受典型房扑导管消融的32例成人先心病患者为研究对象,并对消融术后新发房颤的发生情况随访.分析新发房颤的发生率及高危因素.结果 平均随访(...     

Angiotensin II receptor blockade reduces new-onset atrial fibrillation and subsequent stroke compared to atenolol: the Losartan Intervention For End Point Reduction in Hypertension (LIFE) study

OBJECTIVES: This study was designed to evaluate whether different antihypertensive treatment regimens with similar blood pressure reduction have different effects on new-onset atrial fibrillation (AF). BACKGROUND: It is unknown whether angiotensin II receptor blockade is better than beta-blockade in preventing new-onset AF. METHODS: In the Losartan Intervention For Endpoint reduction in hypertension (LIFE) study 9,193 hypertensive patients and patients with electrocardiogram-documented left ventricular hypertrophy were randomized to once-daily losartan- or atenolol-based antihypertensive therapy. Electrocardiograms were Minnesota coded centrally, and 8,851 patients without AF by electrocardiogram or history, who were thus at risk of developing AF, were followed for 4.8 +/- 1.0 years. RESULTS: New-onset AF occurred in 150 patients randomized to losartan versus 221 to atenolol (6.8 vs. 10.1 per 1,000 person-years; relative risk 0.67, 95% confidence interval [CI] 0.55 to 0.83, p < 0.001) despite similar blood pressure reduction. Patients receiving losartan tended to stay in sinus rhythm longer (1,809 +/- 225 vs. 1,709 +/- 254 days from baseline, p = 0.057) than those receiving atenolol. Moreover, patients with new-onset AF had two-, three- and fivefold increased rates, respectively, of cardiovascular events, stroke, and hospitalization for heart failure. There were fewer composite end points (n = 31 vs. 51, hazard ratio = 0.60, 95% CI 0.38 to 0.94, p = 0.03) and strokes (n = 19 vs. 38, hazard ratio = 0.49, 95% CI 0.29 to 0.86, p = 0.01) in patients who developed new-onset AF in the losartan compared to the atenolol treatment arm of the study. Furthermore, Cox regression analysis showed that losartan (21% risk reduction) and new-onset AF both independently predicted stroke even when adjusting for traditional risk factors. CONCLUSIONS: Our novel finding is that new-onset AF and associated stroke were significantly reduced by losartan- compared to atenolol-based antihypertensive treatment with similar blood pressure reduction.     

Atrial fibrillation and thromboembolic events prevention. State of the art

Atrial Fibrillation (AF) is a common cardiac arrhythmia and stroke is its most devasting complication. The rate of ischemic stroke among people with AF is approximately six times that of people without AF and varies importantely with coexistent cardiovascular diseases; therefore stratification of AF patients into those at high and low risk of thromboembolism has become a crucial determinant of optimal antithrombotic prophylaxis. Multivaria-te analyses of prospective studies consistently show prior TIA/stroke, diabetes, age, heart failure to be independently predictive of stroke; left ventricular dysfunction is also strongly associated with stroke risk. Several randomized clinical trials demonstrated that treatment with adjusted-dose warfarin reduces the risk of stroke in AF patients by about two thirds. The efficacy of aspirin for prevention of stroke is controversial, but supported by pooled results of 3 placebo-controlled trials yelding a 21% reduction in stroke. The inherent risk of stroke should be considered in selection of AF patients for lifelong anticoagulation. Patients with AF and a recent stroke or TIA or multiple risk factors for stroke are likely to benefit from anticoagulation therapy; at present a target INR 2,5 appears optimal for most patients, although INR closer to 2.0 may be safer for patients at increased risk for bleeding events. The addition of aspirin to low- dose warfarin regimen does not provide any significant benefits and should be avoided. Therapy with aspirin is appropriate for patients who are at low risk of stroke or are unable to receive anticoagulants. AF patients treated with aspirin, should be periodically evaluated for development of high-risk features favoring anticoagulation.     

Atrial fibrillation and cardioembolic stroke

The most disabling consequence of atrial fibrillation (AF) is stroke. In the elderly, AF is the single most important cause of stroke. The risk of stroke is increased at least 6-fold in subjects with AF. Strokes in patients with AF are in general severe, associated with higher risk of fatality and prone to early and long-term recurrence. The cardiac origin of stroke can be strongly suspected by anamnesis, clinical examination and findings on neuroimaging. Paroxysmal AF is an important cause of brain embolism, that is often difficult to document. Risk factors for stroke in AF include: previous embolism (including previous transient ischaemic attack (TIA), or ischaemic stroke), age >65 years, structural cardiac disease, rheumatic or other significant valvular heart disease, valvular artificial prosthesis, hypertension, heart failure and significant left ventricular systolic dysfunction, diabetes and coronary disease. All AF patients with TIA or stroke have a formal indication for long-term anticoagulation. Only patients without risk factors or with contraindications to warfarin should be put on aspirin. Treating 1 000 patients with AF for 1 year with oral anticoagulants rather than aspirin would prevent 23 ischaemic strokes while causing 9 major bleedings. Despite its enormous preventive potential, oral anticoagulants are underused in AF, because treating physicians often have lack of knowledge about trials and guidelines, underestimate the benefits and overestimate the risks associated with continuous oral anticoagulation. The introduction of anticoagulants that do not need frequent control tests, such as ximelagatran, will increase the proportion of AF patients with risk factors for stroke who are anticoagulated. There is no evidence to support routine immediate anticoagulation in acute ischeamic stroke associated with AF.     

Impact of new-onset diabetes mellitus on development of atrial fibrillation and heart failure in high-risk hypertension (from the VALUE Trial)

Hypertension and diabetes mellitus (DM) are known risk factors for atrial fibrillation (AF). We investigated the influence of new-onset DM on developing AF in the VALUE trial population of high-risk hypertensive patients. Five thousand two hundred fifty patients of the 15,245 participants in the VALUE trial had DM at baseline and 1,298 of the initially nondiabetic patients developed DM during the average 4.2-year follow-up. The presence of AF was determined by central analyzed electrocardiograms at baseline and changes were assessed yearly. Patients without AF at baseline and with any AF by later electrocardiograms were defined as patients with new-onset AF. Patients with new-onset and baseline DM were compared with patients without DM by a Cox regression model with adjustment for prespecified covariates. Five hundred fifty-one patients developed new-onset AF during the trial. Patients with new-onset DM had a significantly higher event rate of new-onset AF with a hazard ratio of 1.49 (1.14 to 1.94, p = 0.0031) compared with patients without DM, and there was a trend toward more AF in patients with DM at baseline. Patients with new-onset DM had also more persistent AF (hazard ratio 1.87, 1.28 to 2.74, p = 0.0014). Patients with new-onset DM and AF had a hazard ratio of 3.56 for heart failure (2.86 to 4.44, p <0.0001) compared with patients with new-onset DM without AF. In conclusion, hypertensive patients who developed DM during the VALUE trial had more AF than did patients without DM, and this may explain some of their concomitant high risk of hospitalization for heart failure.     

Diabetes mellitus and atrial fibrillation: perspectives on epidemiological and pathophysiological links

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, which is also associated with a substantial risk of mortality and morbidity from stroke, thromboembolism, heart failure and hospitalisations. On a epidemiological basis, diabetes mellitus is commonly associated with AF. Nonetheless, AF is also associated with vascular disease and hypertension, which are themselves intimately linked to diabetes. Indeed, the precise pathophysiological and clinical relationships between AF and diabetes mellitus are not completely understood. What we do know is that both diabetes and AF are individually bad for our patients, and the presence of both requires aggressive management strategies.     

Impact of new-onset diabetes mellitus on cardiac outcomes in the Valsartan Antihypertensive Long-term Use Evaluation (VALUE) trial population

There has been a lot of interest about new-onset diabetes mellitus in recent hypertension trials, but the implications of diabetes development on cardiac outcomes have not been known. In the Valsartan Antihypertensive Long-Term Use Evaluation trial, 15 245 high-risk patients were followed for an average of 4.2 years. At baseline, 5250 patients were diabetic by the 1999 World Health Organization criteria, and among the 9995 nondiabetic patients, 1298 patients developed diabetes during follow-up. We have investigated the influence of diabetes development on outcomes in the Valsartan Antihypertensive Long-Term Use Evaluation trial. The patients with diabetes at baseline and new-onset diabetes were compared with patients who did not develop diabetes by a Cox regression model with adjustment for prespecified covariates (age, diabetes status, left ventricular hypertrophy, baseline coronary heart disease, and randomized study treatment). Patients with diabetes at baseline had the highest cardiac morbidity defined as myocardial infarction and heart failure with a hazard ratio of 2.20 (95% CI: 1.95 to 2.49). The patients with new-onset diabetes had significantly higher cardiac morbidity, especially more congestive heart failure, than those without diabetes, with a hazard ratio of 1.43 (95% CI: 1.16 to 1.77). This indicates that patients who develop diabetes during antihypertensive treatment have cardiac morbidity intermediate between diabetic subjects and those subjects who never had diabetes and that it is of importance to find these patients at risk of diabetes development and optimize lifestyle and medical treatment.     

急性心肌梗死患者CHADS2评分与他汀类药物治疗对新发心房颤动预防作用的相关性

目的 确认CHADS2[C（congestive heart failure）H （hypertension）A （age）D （diabetes Mellitus）S2（prior stroke or transient ischemic attack）]危险评分是否与急性心肌梗死（acute myocardial infarction,AMI）患者新发心房颤动（atrial fibrillation,AF）存在相关性,以及是否有助于确定AMI后从使用他汀类药物预防AF发生的最大获益者.方法 连续性收集于2011年10月至2013年11月就诊于广东省人民医院的724例AMI患者.根据CHADS2评分,所有患者被分为3组：A组=0分;B组=1～2分;C组=3～6分.研究终点是患者在住院期间出现的持续时间超过30 s的新发AF发作.结果 78例患者（10.8％）出现新发AF,而682例患者（94.2％）接受了他汀类药物治疗.新发AF的发病率从A组到C组逐步升高,组间比较差异有统计学意义（P=0.017）.他汀类药物的使用（OR =0.22,95％CI=0.06～0.85）和CHADS2评分（OR=1.53,95％ CI=1.02～2.28）均为AMI患者新发AF的独立危险因素.CHADS2评分≤2的患者的C-反应蛋白浓度显著降低,且如果他们服用他汀类药物,新发AF的风险显著降低（P＜0.05）.多因素回归分析显示,对CHADS2评分≤2的患者使用他汀类药物预防新发AF是有效的（OR=0.34,95％CI=0.14～0.81）.结论 CHADS2评分有助于确定AMI后从使用他汀类药物预防AF发生的最大获益者.     

Canadian Cardiovascular Society atrial fibrillation guidelines 2010: management of recent-onset atrial fibrillation and flutter in the emergency department

Atrial fibrillation (AF) is the most common arrhythmia managed by emergency physicians. There is increasing evidence that most patients with recent-onset AF or atrial flutter (AFL) can be safely managed in the emergency department (ED) without the need for hospital admission. The priorities for ED management of recent-onset AF/AFL include rapid assessment of potential hemodynamic instability and identification and treatment of the underlying or precipitating cause. A careful evaluation of the patient's history should be performed to determine the time of onset of the arrhythmia. All patients should be stratified using a predictive index for the risk of stroke (eg, CHADS(2)). For stable patients with recent-onset AF/AFL, a strategy of either rate control or rhythm control could be selected based on multiple factors including the duration of AF and the severity of symptoms. If a strategy of rhythm control has been selected, either electrical or pharmacologic cardioversion may be used. Before proceeding to cardioversion in the absence of systemic anticoagulation, physicians must be confident that the duration of AF/AFL is clearly <48 hours and that the patient is not at a particularly high risk of stroke. When the duration of AF/AFL is >48 hours or uncertain, rate control should be optimized first and the patients should receive therapeutic anticoagulation for 3 weeks before and 4 weeks after planned cardioversion. Adequate follow-up of patients with recent-onset AF/AFL is recommended to identify structural heart disease and evaluate the need for long-term antithrombotic or antiarrhythmic therapy.     

左心房黏液瘤术后新发房性心律失常的患者行导管消融的有效性与安全性初探

目的初步探讨左心房黏液瘤外科术后新发房性心律失常的患者接受导管消融的安全性与有效性。方法回顾性选取北京安贞医院2014年9月至2019年11月左心房黏液瘤术后新发房性心律失常并接受导管消融治疗的患者9例。收集患者的基线临床数据、消融术中参数和围术期严重不良事件,并随访导管消融术后心律失常复发情况和临床预后,采用Kaplan-Meier生存曲线分析导管消融术后窦性心律维持率。结果9例患者年龄(55.8±9.1)岁,男性3例(3/9),阵发性心房颤动(房颤)3例(3/9),心房扑动(房扑)或房性心动过速(房速)6例(6/9)。所有患者均成功完成导管消融治疗,围术期均未发生卒中、心包积液、心脏压塞、血管并发症及大出血事件。随访40.0(27.5,55.5)个月,9例患者中有6例(6/9)初次消融术后维持窦性心律,总体窦性心律维持比例为2/3。3例房颤患者中有1例(1/3)出现早期房颤复发(术后3个月),6例房速或房扑患者中有2例(2/6)房扑患者出现极晚期新发房颤和/或复发房扑(分别为术后19、29个月)。3例复发患者中有2例接受再次消融,其中1例维持窦性心律。所有患者随访期间未复发黏液瘤,未发生死亡、卒中、急性心肌梗死等事件。结论左心房黏液瘤外科术后新发房性心律失常患者接受导管消融安全、有效,可以作为一项治疗选择。     

Prevention of Atrial Fibrillation in Cardiac Surgery: Time to Consider a Multimodality Pharmacological Approach

Atrial fibrillation (AF) is very common within the first 5 days of cardiac surgery. It is associated with significant morbidity including stroke, ventricular arrhythmias, myocardial infarction, heart failure, acute kidney injury, prolonged hospital stay, and also short‐ and long‐term mortality. The underlying mechanisms of developing AF after cardiac surgery are multifactorial; risk factors may include advanced age, withdrawal of beta‐blockers and angiotensin‐converting‐enzyme inhibitors, valve surgery, obesity, increased left atrial size, and diastolic dysfunction. There are many pharmacological options in preventing AF, but none of them are effective for all patients and they all have significant limitations. Beta‐blockers may reduce the incidence of AF by more than a third, but bradycardia, hypotension, or exacerbation of heart failure often limit their utility postoperatively. Recent evidence suggests that class III antiarrhythmic drugs, sotalol and amiodarone, are more effective than beta‐blockers, but they both share similar hemodynamic side effects of beta‐blockers. Magnesium, antiinflammatory drugs such as statins, omega fatty acids, and low‐dose corticosteroids also have some efficacy and they have the advantages of not causing significant hemodynamic side effects. Data on effectiveness of calcium channel blockers, digoxin, alpha‐2 agonists, sodium nitroprusside, and N‐acetylcysteine are more limited. Because the pathogenesis of AF is multifactorial, a combination of drugs with different pharmacological actions may have additive or synergistic effect in preventing AF after cardiac surgery. Randomized controlled trials evaluating the effectiveness of a multimodality pharmacological approach in patients at high‐risk of AF after cardiac surgery are needed.     

Rhythm- and rate-controlling effects of dronedarone in patients with atrial fibrillation (from the ATHENA trial)

Dronedarone is a multi-channel-blocking drug for the treatment of patients with atrial fibrillation (AF) or atrial flutter (AFL) with rate- and rhythm-controlling properties. A Placebo-Controlled, Double-Blind, Parallel Arm Trial to Assess the Efficacy of Dronedarone 400 mg b.i.d. for the Prevention of Cardiovascular Hospitalization or Death from Any Cause in Patients With Atrial Fibrillation/Atrial Flutter (ATHENA) demonstrated that dronedarone reduced the risk for first cardiovascular hospitalization or death from any cause. The aim of this post hoc analysis was to evaluate the rhythm- and rate-controlling properties of dronedarone in the ATHENA trial. Patients were randomized to dronedarone 400 mg twice daily (n = 2,301) or placebo (n = 2,327). Electrocardiographic tracings were classified for AF or AFL or sinus rhythm. Patients with AF or AFL on every postbaseline electrocardiogram were classified as having permanent AF or AFL. All electrical cardioversions were documented. The use of rate-controlling medications was equally distributed in the 2 treatment groups. The median time to first AF or AFL recurrence of patients in sinus rhythm at baseline was 498 days in placebo patients and 737 days in dronedarone patients (hazard ratio 0.749, 95% confidence interval 0.681 to 0.824, p <0.001). In the dronedarone group, 339 patients (15%) had ≥1 electrical cardioversion, compared to 481 (21%) in the placebo group (hazard ratio 0.684, 95% confidence interval 0.596 to 0.786, p <0.001). The likelihood of permanent AF or AFL was lower with dronedarone (178 patients [7.6%]) compared to placebo (295 patients [12.8%]) (p <0.001). At the time of first AF or AFL recurrence, the mean heart rates were 85.3 and 95.5 beats/min in the dronedarone and placebo groups, respectively (p <0.001). In conclusion, dronedarone demonstrated both rhythm- and rate-controlling properties in ATHENA. These effects are likely to contribute to the reduction of important clinical outcomes observed in this trial.     

The effectiveness of SGLT2 inhibitor in the incidence of atrial fibrillation/atrial flutter in patients with type 2 diabetes mellitus/heart failure: a systematic review and meta-analysis

BackgroundType 2 diabetes mellitus (T2D) and heart failure (HF) are closely related to the increased risk of atrial fibrillation (AF)/atrial flutter (AFL). However, massive clinical studies have shown that sodium glucose cotransporter 2 inhibitor (SGLT2i) affects the occurrence of AF/AFL and its complications, but the promoting or inhibitory effect of SGLT2i on AF/AFL and its complications and the exact probability is not clear, meta-analysis can combine the existing research data to easily solve the clinical problems.MethodsWe performed a search in the registers of ClinicalTrials.gov from it,s inception to March 2021 to evaluate the occurrence of AF/AFL adverse events in SGLT2i in patients with T2D/HF. Almost all of the included studies were double-blind parallel allocation randomized controlled studies, and only one was open. The control groups all included placebo, some of which also included glimepiride, metformin, liraglutide, etc. Quality risk assessment of the included randomized controlled trials (RCTs) was conducted using Cochrane RoB 2.0., and the publication bias assessment was conducted using STATA 17.0. The odds ratio (OR) combined effect of 95% confidence interval (CI) was used for bivariate variables.ResultsWe included data from 22 confirmed trials that included 52,951 T2D/HF patients. The studies had no risk of bias. Analysis of the cumulative results showed that compared with placebo, SGLT2i can significantly reduce the incidence of AF/AFL by 18% (OR =0.82, 95% CI: 0.73 to 0.93, P=0.002), and reduce the incidence of arrhythmia by 14% (OR =0.86, 95% CI: 0.79 to 0.94, P=0.0006); among them, the incidence of AF/AFL in T2D patients was reduced by 20% (OR =0.80, 95% CI: 0.69 to 0.92, P=0.002); Dapagliflozin reduced the incidence of AF/AFL by 15% (OR =0.85, 95% CI: 0.74 to 0.98, P=0.03); the incidence of intracardiac thrombosis decreased by 69% (OR =0.31, 95% CI: 0.10 to 0.91, P=0.03), while the incidence of AF/AFL in women decreased by 17% (OR =0.83, 95% CI: 0.72 to 0.94, P=0.004).DiscussionThis article provides a new direction for the use of SGLT2i, and hopefully it can provide certain theoretical basis for the broader clinical indications of SGLT2i in the future.     

Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in atherosclerosis

Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) effectively interfere with the renin-angiotensin system and exert various beneficial actions on cardiac and vascular structure and function, beyond their blood pressure-lowering effects. Randomized, controlled clinical trials have shown that ACE inhibitors improve endothelial function, cardiac and vascular remodeling, retard the anatomic progression of atherosclerosis, and reduce the risk of myocardial infarction, stroke, and cardiovascular death. Therefore, these agents are recommended in the treatment of a wide range of patients at risk for adverse cardiovascular outcomes, including those with coronary disease, prior stroke, peripheral arterial disease, high-risk diabetes, hypertension, and heart failure. ARBs are effective blood pressure-lowering and renoprotective agents and can be used in heart failure in patients who do not tolerate ACE inhibitors. The role of ARBs in the prevention of atherosclerosis and its sequelae is currently under investigation. The use of combined ACE inhibitor plus ARB therapy offers theoretical advantages over the use of each of these agents alone and is also under investigation in large, randomized clinical trials.     

Angiotensin converting enzyme inhibitors for prevention of new-onset type 2 diabetes mellitus: A meta-analysis of 72,128 patients

Backgroud

Angiotensin converting enzyme inhibitors (ACEIs) have been linked to reduced risk of new-onset diabetes, but the evidence was insufficient.

Objective and methods

The aim of this study was to evaluate the effect of ACEIs on the development of new-onset type 2 diabetes. Randomized controlled trials (RCTs) about ACEIs and new-onset diabetes were identified by electronic and manual searches.

Results

Nine RCTs with 92,404 patients (72,128 non-diabetic patients at baseline) were included in this study. Compared with control group, incidence of new-onset diabetes was significantly reduced in the ACEIs group [OR 0.80, (0.71, 0.91)], irrespective of achieved blood pressure levels at the follow-up. ACEIs therapy was associated with significant reduction in the risk of new-onset diabetes compared with beta-blockers/diuretics [OR 0.78, (0.65, 0.93)], placebo [OR 0.79, (0.64, 0.96)], or calcium channel blockers [OR 0.85, (0.73, 0.99)]. ACEIs treatment was associated with significant reduction in the risk of new-onset diabetes in patients with hypertension [OR 0.80, (0.68, 0.93)], coronary artery disease (CAD) or cardiovascular disease [OR 0.83, (0.68, 1.00)], or heart failure [OR 0.22, (0.10, 0.47)]. Among patients with impaired glucose tolerance or impaired fasting glucose, ramipril did not significantly reduce the incidence of diabetes [OR 0.91, (0.79, 1.05)], but significantly increased regression to normoglycemia.

Conclusion

ACEIs have beneficial effects in preventing new-onset diabetes. ACEIs provide additional benefits of lowering the risk of new-onset diabetes in patients with hypertension, CAD or other cardiovascular disease.     

Comparing the guidelines: anticoagulation therapy to optimize stroke prevention in patients with atrial fibrillation

Atrial fibrillation (AF) is an important risk factor for stroke. According to a pooled analysis of controlled clinical trials with warfarin, anticoagulation therapy reduces stroke risk by 62%. However, clinicians must decide whether the benefit of long-term anticoagulation therapy with available agents outweighs the risk of bleeding for individual patients. Guidelines issued by the American College of Chest Physicians and by the joint American College of Cardiology, American Heart Association, and the European Society of Cardiology task force recommend antithrombotic therapy to protect AF patients from stroke based on risk-stratification algorithms. Risk factors for stroke AF patients include age > or =75 years; hypertension; thyrotoxicosis; diabetes; cardiovascular disease; congestive heart failure; and history of stroke, transient ischemic attack, or thromboembolism. Patients at high risk for stroke experience greater absolute benefit from anticoagulation therapy than patients at low risk. The guidelines are consistent in recommendations for high-risk patients (warfarin therapy, international normalized ratio 2.0 to 3.0) and low-risk patients (aspirin 325 mg), but differ for intermediate-risk patients with diabetes or heart disease. The guidelines continue to evolve, and future guidelines are likely to incorporate new clinical data, including the CHADS(2) algorithm for determining risk and the results of the Atrial Fibrillation Follow-up Investigation of Rhythm Management trial, the Rate Control versus Electrical Cardioversion for Persistent Atrial Fibrillation study, and the Stroke Prevention Using an Oral Thrombin Inhibitor in Atrial Fibrillation II to V trials.     

Canadian Cardiovascular Society atrial fibrillation guidelines 2010: rate and rhythm management

The goals of atrial fibrillation (AF) and atrial flutter (AFL) arrhythmia management are to alleviate patient symptoms, improve patient quality of life, and minimize the morbidity associated with AF and AFL. Arrhythmia management usually commences with drugs to slow the ventricular rate. The addition of class I or class III antiarrhythmic drugs for restoration or maintenance of sinus rhythm is largely determined by patient symptoms and preferences. For rate control, treatment of persistent or permanent AF and AFL should aim for a resting heart rate of <100 beats per minute. Beta-blockers or nondihydropyridine calcium channel blockers are the initial therapy for rate control of AF and AFL in most patients without a history of myocardial infarction or left ventricular dysfunction. Digoxin is not recommended as monotherapy for rate control in active patients. Digoxin and dronedarone may be used in combination with other agents to optimize rate control. The first-choice antiarrhythmic drug for maintenance of sinus rhythm in patients with non structural heart disease can be any one of dronedarone, flecainide, propafenone, or sotalol. In patients with abnormal ventricular function but left ventricular ejection fraction >35%, dronedarone, sotalol, or amiodarone is recommended. In patients with left ventricular ejection fraction <35%, amiodarone is the only drug usually recommended. Intermittent antiarrhythmic drug therapy ("pill in the pocket") may be considered in symptomatic patients with infrequent, longer-lasting episodes of AF or AFL as an alternative to daily antiarrhythmic therapy. Referral for ablation of AF may be considered for patients who remain symptomatic after adequate trials of antiarrhythmic drug therapy and in whom a rhythm control strategy remains desired.     

Is atrial fibrillation an independent marker of cardiovascular risk?

Atrial fibrillation (AF) is the most frequent cardiac arrhythmia and its prevalence rises with age. AF may cause stroke and heart failure but the relationship between AF and mortality is less clear. It is difficult to determine if cardiovascular events in patients with AF are attributable to the arrhythmia itself or if they are merely related to the comorbidities frequently associated with AF. Review of the literature suggests that lone AF (without structural heart disease), a rare clinical entity except in young patients, is not an independent risk factor for mortality. On the other hand, if illnesses usually associated with AF are present (hypertension, heart failure...), AF has a negative impact on outcome in terms of survival and morbidity. Current antiarrhythmic medications have not shown reduction in mortality of AF patients, but new agents and catheter ablation are promising paths to explore in order to decrease AF burden.